body {
    padding-top: 20px;
}

.fenye {
    margin: 20px;
    display: flex;
    /* 设置元素在主轴方向的水平居中 */
    justify-content: center;
    /* 设置元素在侧轴（垂直）方向的垂直居中 */
    align-items: center;
}

.course img {
    width: 100%;
    height: 100%;
}

.top1 {
    padding-top: 20px;
}

.top img {
    width: 340px;
    height: 220px;
    border-radius: 5%;
}

.page {
    text-align: center;
}

.container .btn {
    background: transparent;
    border: 1px solid #40D2B1;
    /*dotted solid double dashed;点状 实线 双线 虚线*/
    border-radius: 4px;
    color: #40D2B1;
    margin-top: 20px;
    margin-bottom: 30px;
    padding: 8px 20px;
    transition: all 0.5s;
}

.container .btn:hover {
    background: #58f17e;
    color: #fff;
}

.col-md-3 {
    margin-top: 30px;
    display: inline-block;
    padding-bottom: 50px;
    padding: 15px;
    cursor: pointer;
    transition: all 0.6s;
    border-radius: 5px;
}

.col-md-3:hover {
    background: #ffffe5;
    box-shadow: 1px 1px 4px #ccc;
    transform: scale(0.9)
}